犬腺病毒纤突蛋白基因功能区的比较分析

根据GenBank中已发表的CAV纤突基因序列，设计合成4对8条引物，用已建立的PCR方法，对犬2型腺病毒沈阳分离株第5代强毒经蚀斑克隆驯化的第60代毒弱毒（SY-V60）和犬1型腺病毒长春犬株（CCC-V6）的纤突基因进行了扩增，PCR产物经纯化后进行基因序列测定，测定结果经拼接后得到一个由1632和1629个核苷酸组成的纤突蛋白全基因序列，分别编码543和542个氨基酸。犬2型腺病毒（SY-V60）与犬1型腺病毒（CCC-V6）的纤突基因的同源性达到80.48%。犬2型腺病毒（SY-V60）与犬1型腺病毒（CCC-V6）纤突基因的同源性达到80.48%；根据犬的腺病毒与人2型腺病毒纤突蛋白的序列同源性比较结果，推测了犬腺病毒纤突蛋白的尾（tail)、轴（shaft)，结（knob)三个功能区的氨基酸序列，2个型之间的尾区同源性为76.9%；轴区同源性为78.59%；其结区同源性为83.24%，而同型毒株之间结和尾区同源性较高，轴区同源性较低。

Comparison and Analysis of the CAV Fiber Protein Structure Domain

The CAV-1 multiplies in vascular epithelium causes a general infection characterized as hepatitis.The CAV-2 is associated with upper respiratory infection and intestinal syndromes.Adenovirus fiber protein(Fip)plays a crucial role in infection by attaching the virus to a specific cell-surface receptor.In order to further explain the mechanism of difference in cell tropism and virulence between Cav-1 and CAV-2 on molecular level,the Fip genes of the CAV-2 attenuated SY-V60.The CAV-1 and CCC-V6 had been sequenced and compared with the standard human adenovirud 2 type (Had2) strains which were extracted from the GenBank database.We designed 2 pairs of primers according to CAV Fip gene to amplify the Fip genes with PCR method.Complete Fip gene sequences of SY-V60 and CCC-V6 strains were shown to be consist of 1629nt to conduct code 542 amino acids and 1631nt to conduct code 543 amino acids from ATG start code.Homology of Fip between CAV-1 and CAV-2 is 80.48 percent.By homology comparison with the human adenovirud 2 type Fip sequence,we deduced tail,shaft and knob domains of CAV that provided a solid foundation for the further study of the cell tropism of CAV.Homology of tail domains between CAV-1 and CAV-2 is 76.9 percent, 78.59 percent in shaft domain and 83.24 percent in knob domain.Homology of fiber protein structure tail domain and knob domain is higher, shaft domain is less than that of the same CAV type.